An example of the latter situation, as set forth above, is a voiceprint recognition task for a speaker (class) previously enrolled using speech samples collected over a microphone of a type A but later being tested on samples recorded over a microphone type B. It has been widely recognized that environment/channel mismatches cause more or less great a degradation of the system recognition accuracy and represent one of the major challenges in the pattern recognition area. This is covered in at least the following references: “HTIMIT and LLHDB: Speech Corpora for the Study of Handset Transducer Effects”, International Conference on Acoustics, Speech, and Signal Processing, Munich, Germany, May 1997, by D. A. Raynolds (microphone mismatch in speech recognition); and “The IBM system for the NIST 2002 cellular speaker verification evaluation”, International Conference on Acoustics, Speech, and Signal Processing, Hong Kong, April 2003, by G. N. Ramaswamy et al. (state of the art technology, including mismatched conditions). A need has thus been recognized in connection with solving such problems, among others.